A filtering water tank is a core member of a water filtration cleaner, and uses clean water as filter materials, so as to replace structures such as a dust cup or a dust box that are commonly used in a traditional cleaner, without replacing consumables including dust bags or HEPA meshes additionally. Moreover, dust can be significantly filtered out by water, and the water mixed with the dust can be dumped directly without generating the problem of dust raising, thereby achieving an effect of ultimate cleaning. Since an air intake pipe serves as an important member in the filtering water tank, a performance of the air intake pipe directly influences a filtering capacity of water to a dust-laden air and a subsequent water-air separation effect.
The air intake pipe in the related art may be configured as a circular pipe or rectangle pipe having a constant cross section. However, since such air intake pipe is configured to have a constant sectional shape, big dust-laden bubbles equal to the cross section of the air intake pipe in size will be introduced into the water, and these bubbles are difficult to be broken into bubbles having a smaller size, thus resulting in a poor effect of mixing the dust with water. Another air intake pipe in the related art is designed to have a non-constant cross section, and a simple stamping process generally is performed at a pipe mouth of the circular pipe so as to stamp the pipe mouth into a flat pipe. However, a cross-sectional flow area of such air intake pipe varies unevenly, and a flow loss of an air flow is great, thus increasing an energy consumption. In addition, another air intake pipe in the related art is designed as a circular pipe having a convergent cross section. However, a flow cross section of such air intake pipe has an equal length in each direction, and the cross-sectional flow area decreases evenly in a flowing direction, thus tending to result in a problem that large-particle garbage blocks the air intake pipe. Moreover, both the air intake pipe having the constant cross section and the air intake pipe having the convergent cross section may cause a violent impact of air on the water, such that the bubble is broken with a large noise and a water-air separation is influenced.